My guess is you have chopped the arms off the main body so there is not much overlap. What I think you need to do is make the torso / chest look good without the arms. Then have complete arms with a full U shape at the end that overlaps the body. Sometimes I even put a circle on the torso the width of the upper arm at the shoulders (so half a circle sticks out where the arm joins. I then set the origin point to the center of the circle.
Think of it like two piecces of paper - one for the torso, one for the arm. You then swivel the arm at the origin point so it rotates. If there is not much overlap it looks bad as you will get a gap between the arm and the body. If the two layers of artwork have more overlap it looks more natural.
Thanks...that helped. Going forward, I’ll take those types of things in consideration.